Carburetor



Dec. 20, 1927.

P. W. ENSIGN CARBURETOR Filed nz si, L f 4 Q n o 9 Z f 4\ 2 o 9, 2 I 6 W( :1....: 1.\o a f 4 @a 6 3 w 3 l, 5 Q 3 I. a J Mf o W Patented Dec. 20, 1927.

UNITED STATES PATENT OFFICE.

PAUL WILFRED ENSIGN, OF SOUTH PASAIDENA, CALIFORNIA, ASSIGNOB T0 ENBIGN CABBURETOB GOMPAN Y, 0F LOS ANGELES, CALIFORNIA, A CORPORATION OF CALI- FORNIA.

CARBUBETOB.

Application Med April 13, 1922. Serial No. 552,322.

This application relates to implrovements over the invention' set forth in t e copending a plication filed by Roy Francis Ensign, ovember 25, 1919, Serial No. 340,658.

This invention relates to improvements in carburetors for internal combustion engines whereb better and quicker acceleration o interna combustion engines of the automotive type is made possible.

An ob'ect of this invention is to provide means w ereby the idling mixture for such engines may be more perfectly controlled.

An object is to provide by simple means, ample acceleratinor fuel for such engines, to cause gradual de ivery of such accelerating or excess fuel upon opening the throttle from idling position, and also to accumulate ac-` celerating fuel from the main fue] stream upon closing the throttle` and to hold 1t 1n readiness for subsequent acceleration.

An ob'ect is to provide simple improved means w ereby fuel may be drawn from-the fuel suppl and added to such accumulated fuel, and t ence transmitted to the mam .air stream to keep the engine running during idling. w

Another Objectis to provide means whereby a lpredetermined uantity of accelerating -fuel ma be accumu ated upon closing the engine t rottle.

Another object is to provide simple and more effective means for rv rulating the idling mixture.

Another object is to facilitate starting the engine when hot without using the starting choke.

Another object is to make possible perfect control of idling mixture and to furnish sustained accelerating fuel for any ty e of carburetor in which the fuel flows ownward from the fuel supply chamber to the main air stream.

Other objects, advantages and features of invention may appear from the accompanyin drawing, the subjoined detail description angl the appended claims.

The accompanying drawing illustrates the invention.`

Figure'l is a vertical section of a carl` rotor provided with the improvement. The parts are shown in position for idling. and the liquids are shown in osition of rest.

Fig. 2 is an enlar fragmento] axial section of the carburetor shown in Fig. 1, with the liquids shown in the position assumed during idling operation of the engine. Fig. 3 is a section in the scale of Fig. 2 on irregular line w3, Figs. 1 and 2.

The invention is applicable to various types of carburetors of the down iow fuel feed tfpe or those in which the fuel is delivere to the mixture passage at a oint below the constant fuel level and in t e drawings is shown as applied in a vortex type of carburetor in which the air inlet 1 admits air past the choke valve 2 tangcntially into the. mixing chamber 3 where it forms the main air stream that receives the fuel delivered from the constant level fuel chamber 4 through fuel orifice 5 into the fuel suction chamber 6 where the fuel overflows through the intake 7 of the fuel passage which comprises a drop pipe 8 where the fuel asses downward toward the mixing cham er 3.

In the present invention the fuel passage comprises a reservoir 9 which is positioned above the lower end of and encircles the lower portion of the dro pipe 8 with which it communicates throng 1 downwardly extendlng leads 10 which terminate at the bottom of said reservoir. A separable sleeve 12 mounted on body 1l forms the outer wall of the reservoir and is provided at its top with orifices 13 to permit discharge of the fuel from the reservoir into the main air stream in the mixing chamber 3.

As is common the suction chamber 6 is provided with a restricted air port 14 admitting air into the suction chamber under all conditions of carburetor operation. This air is admitted through the equalizer tube 15 leading from the air inlet 1.

The mixing chamber o ens into the mixture assage 16 which 1s controlled by a throtte'l'.

There is provided a by-pass consisting of a duct 18 having a suction port 19 and communicating through an annular chamber 20 with a suction passage 21 which is extended by a tube 22 t0 the upper portion of the suction chamber above the level of the fuel therein. This by-pass is also provided with an unregulated vent 23 and with a regulated vent 24.

To regulate the vent 24, there is provided the needle valve 25 held in position by the retainer s ring 26.

The car uretor is adapted for attachment to an engine manifold, a fragment of which is shown at 27.

The choke valve 2 is fixed on a shaft 28 that is provided at its upper end with a movable stop 29 adapted to engage the sta'- tionary stop 30, and provided at its louer end with a lever arm 31 to which may be attached a control wire, not shown, by means of the swivel 32 held by the screw 33. By this means the choke valve may be closed or opened as may be desired for starting and operating the engine.

The constant level fuel chamber is provided with a float 34, which, through the lever 35 and the pivot 36 engages the fuel valve 37 for regulating the height of the fuel in the float chamber. The intake 7 of the fuel passage is at a level amply above the fuel level 38 to avoid tendency to leak. The fuel stands at the same level inside the suction chamber 6 as inthe fuel chamber 4 when the carburetor is not in operation.

By locating the orifices 13 at an appropriate hei ht above the bottom of the reservoir, the fewer portion of the fuel passage including the reservoir 9, will, when` t e carburetor is at rest, contain fuel as shown in Fig. 1, up to the bottom of theu orifices 13 as indicated at level 39.

During idling, this retained fuel, shown in Fig. 2, assumes in the lower end of the fuel passage, a level indicated at 4() which is much higher than the top of the reservoir or the fue level 39 when the engine 1s at rest.

In o eration, the suction from the engine manifo d 27 draws air into the air inlet 1 and through the restricted air port 14, these being the only two places where air is admitted, all of which air comes from the same source, viz, air inlet 1, or in case the carburetor is used without external resistance at 1, such as a heater or air cleaner, the port 14 may be supplied directly from the atmosphere Without the equalizer tube 15. The air enters the mixing chamber 3 tangentially and is set whirling about the center of the mixing chamber, creating therein a vertical depression about the orifices 13. This deression under all load o eration of the carliuretor is communicate through the orificcs 13, the reservoir 9, the leads 10 of the lower end of the fuel passage 8 to the upper end 7 of the fuel passage, and to the suction chamber 6, where it acts on the surface of the liquid fuel in the suction chamber to cause fuel to flow through the fuel orifice and thence to overflow the top of the fuel passage in proper proportions to make a combustible mixture at all air velocities in the air inlet 1.

When the depression in the vortex chamber is not suiliciently great to raise the fuel to the inlet 7 of the fuel passa e which extends above the fuel level 38, t e lower end of the passage 8 is sealed by fuel accumulating therein because the inner ends of the leads 10 are below the level of their outer ends and the orifices 13.

During load operation of the carburetor, the depression in the mixing chamber is suflicient to clear the fuel passage of any accumlated fuel so that fuel and some air flows freely therethrough. Then the engine is slowing down from load operation to idling, the depression beyond the nearly closed throttle, operating through the suction port 19, the duct 18, annular passage 20, suction tube 21, and extension 22 thereof, applies suction from beyond the throttle to the suction chamber 6, which suction is greater than that produced in the suction chamber 6 by the vortex at low speed, vthereby increasing the suction on the fuel orifice 5, and thus increasing the flow of fuel. In effecting this, there takes place a reversal of pressure at the orifices p3 causing a stopping or check of the air flowing from the restricted air port 14 with the fuel through the orifices 13, with a correspondin increase of fuel flow throu h the fuel orifgice 5 and such` reversal imme iately checks the flow of fuel and causes an accumulation of fuel that fills the reservoir 9, the leads 10 of the fuel passage, and the lower end of the drop pipe 8, to some desired height 40.

This height of fuel in the drop pipe 8 iS determined by adjusting the depression in suction chamber' (5. The gieater the depuession, the greater the flow of fuel into the top of the fuel drop pipe 8 and the greater the retardation oi' flou' from the orifices 13. Air and Inikture flowing through the open vent 23 acts to greatly reduce the depression in the duct 18 below the depression applied in duct 18 from beyond the throttle; and the adjusting vent 24, when open, acts in a similar manner; but vent 24 may be adjusted by the needle valve 25 and this will control the depression remaining in the by-pass and sucllO tion chamber (i, und will determine the` height 40 of the accumulated fucl.

During idling the reservoir 9 fills to the top so that the fuel stands therein, being retained by surface tension at the orifices 13 and by the balanced depression in the suction chamberl 6, and the operating fuel during idling is drawn over the top 7 of theI fuel passage b v depression in thc suction chamber 6 and is added to such accumulated fuel from which it fioivs gently out of the orifices 13.

This adjusted height 4() becomes a measure of the suction on the fuel orifice 5 by an action similar to the operation of a siphon.

The improvement in this application consists in the formation of the reservoir 9. In former carburetors of the down flow fuel feed type, the leads l0 to the lower end of the fuel passa e continued straight out to the mixing cham r; and all the accumulated fuel was instantly discharged upon opening the throttle with the result that with some engines there was not enough fuel to give the necessary acceleration; furthermore, when closing the throttle suddenly, if the engine had been running at a high speed, the accumulation would not form a seal quickly enough and hence would not produce the richer mixture for idling, and the motor would die, or quit operating. By the added quantity of fuel provided in the reservoir 9, these-defectsare corrected because the accumulation in the reservoir 9 with a rapidly running motor will close the leads 10 to air flow instantly with a uick accumulation of fuel; and a smooth ciange of speed from big? speed to low speed is accomplished.

i pon opening the' throttle from idling, the depression in the vortex chamber and the change of air flow in the suction chamber from the by-pass to the fuel passage causes the fuel in the lower end of the passage 8 to be immediately delivered throu h the leads 10, the reservoir 9, andy the ori ces 13 to the main air stream and air will immediately follow up this fuel with`the new supply of fuel already started, and further by the delivery of fuel lyin betweenV the orifices 13 and the bottom of t e reservoir 9. Such fuel will be delivered slowly, for the only means of getting it out during operation of the engmeis the depression at the orifices 13 whichdraws air from the suction chamber 6 to act through the leads 10, across the annular space of the reservoir to the orifices 13 acting to deliver the fuel from the reservoir9; and if the throttle isopened only a little wa the suction is not suilicient to remove muc of the fuel from the reservoir 9; but as the throttle is opened more and more, the action becomes more violent with a gradual exhaust of all the fuel lying between the orifices 13 and the bottom of the reservoir 9;

thus continuing to add an increment of in-V creased fuel for speeding up theengine upon suddenly opening the throttle. This actlon makes it possible to accelerate an engine rapidly and smoothly from the low speeds at which speeds it is difficult to acceleratethe fuel flow from the fuel orifice as rapidly as the air flow accelerates through the carburetor. It is thus seen that this accumulated fuel is released and delivered to the main air stream under eddying action from the leads in amounts varying with the opening of the throttle and the velocity of the main air stream.

The heavy fractions of the fuel that are thrown 'on the walls of the mixture chamber 3, finally escape under considerable pressure through the ports 41 into the mixture passage 16. The pressure at which the heavy fractions of fuel are discharged into the mixture passage may amount to one-half pound per square inch at full load and at such pressures air flowing with the fuel in the mixing chamber causes violent atomiza-` tion of the fuel passing through the )orts 41.

Heretofore with 'carburetor s, w en the throttle is closed, and during the period that the engine is slowing down when freed from the clutch, or when the clutch is closed and the automobile is coasting, although the use of fuel in the engine is not re uired, the suction from the engine manifol continues to draw fuel from the fuel supply chamber and such fuel is ordinarily wasted; in this invention the fuel thus drawn from the fuel supply after closing the throttle, is accumulated and retained for accelerating purposes; hence the economy of operation obtained by this improvement is much increased over that of former constructions in which the accelerating fuel is taken as extra fuel direct from the fuel chamber.

From the foregoing it is seen that the reservoir 9`is around the fuel passage and is so constructed that a portion of the accumulated fuel therein will be held out of the direct line of normal fuel flow, and an advantage of such arrangement, and also in having the orifices 13 located above the point of communication of the fuel passage with said reservoir, is the practical assurance that when an automotive vehicle, such as an automobile, is standing' laterally aslant, as on a crowned road,the seal formed by the accumulation of fuel in the reservoir will not be broken under ordinary conditions. In this invention the combined area of the suction port 19 and the unrestricted vent 23 is very large in proportion to the restricted air port 14.

By positioning the ort 19 nearer the pivotal axis of throttle lthan vent 23 and relative to the throttle 17 so that the throttle does not pass port 19 until about quarter load I modify the rate of drop of the depression in duct 18 so that upon slowly opening the throttle there is a gradual reduction during idling of the depression in the chamber 6 instead of a sudden reduction. As the throttle is further opened a high velocity is obtained through the passage 16 and the velocity of the mixture past port 19 and vent 23 is sufficient to cause a depression in duct 18 which is applied in the suction chamber 6, so that with 19 and 23 properly proportioned smooth o eration upon opening the throttle may be o tained. With a very lean mixture proportion at one quarter load, the added de ression from 19 and 23 will gradually mailto the mixture richer until at full load with wide open throttle it reaches the maximum power mixture desired under those con ditions, while at all intermediate throttle positions the mixture is relatively thin and lean in fuel thus producing a control'for economy and flexibility by the size and relative position of holes 19 and 23 of the throttle.

My positioning the port 19 closer to the pivotal axis of throttle 17 it is apparent that the control of the depression in chamber 6 may be varied.

The reservoir in this invention is formed by ase arable perforated ring 12 and groove form in the outer periphery of body h1. By this construction the sizeof the orifices 13 and the jets discharged therethrough as well as the size of the, well or reservoir, may be easily and quickly varied. y

A further advanta e gained is that when a thin mixture is used t e fuel passage will seal uicker than in constructions heretofore used ilue to the smaller area at the bottom of the fuel assage in this novel construction.

I c aim:

1. A carburetorof the character described com risin a suction chamber aV mixinor D chamber and a constant llevel chamber; a fuelorice 'for supplying fuel to the suction chamben-a drop pipe having anl intake end in said suction c amber above the normal levelk of fuel therein, to conduct fuel from said suction chamber during operation of the carburetor; a reservoir encircling the drop pipe; leads connecting said drop pipe wit said reservoir; and orifices in line with said leads openin from said reservoir into said mixin cham er.

2. i carburetor of the character described comprising a suction chamber, a mixing chamber, and a constant level fuel chamber;

a fuel orifice vfor supplying'fuel to the suction chamber; a drop pipe having any intake end in saidsuction chamber above thenorv mal level of fuel thereintoconduct fuel from said suction chamber during operation of the carburetor; a reservoir above the bottom of the drop pipe; leads connecting the bottom of said drop pipe with said'reservoir; means connecting saidreservoir and with said mixing chamber located above the point of communica-tion Aof said leads with said reservoir and in line with said leads.

3. In., a down-flow fuel feed carburetor, a suction chamber, means to supply fuel to said suction chamber, a body having a'dro ppe formed therein; there being in sai 4 dy, leads connecting' said roove and dro pipe; a separable perforated ring mounteld on said body and over said groove to form a reservoir to accumulate fuel from said drop pipe at closed throttle. t

In testimony whereof, I havehereunto set my hand at LosAngelee, California, this 8th day of April, 1922.

PAUL' Easter.

in fuel thus producing a controlfor economy and flexibility by the size and relative position of holes 19 and 23 of the throttle.

My positioning the port 19 closer to the pivotal axis of throttle 17 it is apparent that the control of the depression in chamber 6 maiy be varied.

he reservoir in this invention is formed by a separable perforated ring 12 and groom formed in the outer periphery of body 1'1. By this construction the size of the orifices 13 and the jets discharged therethrough as well as the size of the well or reservoir, may be easily and quickly varied.

A further advantage gained is that when a thin mixture is used the fuel passage will seal uicker than in constructions heretofore used ue to the smaller area at the bottom of the fuel passage in this novel construction.

I claim:

1. A carburetor of the character described comprising a suction chamber, a mixing chamber and a constant level chamber; a fuel orifice for supplying fuel to the suction chamber; a drop ipe having an intake end in said suction chamber above the normal level of fuel therein, to conduct fuel from said suction chamber during operation of the carburetor; a reservoir encircling the dro pipe; leads connecting said drop pi wit said reservoir; and orifices in line with said CER ll'FI GATE Patent No. 1,653,041.

leads openin from said reservoir into said mixin cham er.

2. carburetor of the character described comprising a suction chamber, a mixing chamber, and a. constant level fuel chamber;

'a fuel orifice for supplying fuel to the suction chamber; a drop pipe having an intake end in said suction chamber above the no1 mal level of fuel thereintoconduct fuel from said suction chamber during operation of the carburetor; a reservoir above the bottom of the drop pipe; leads connecting the bottom of said drop pipe with said reservoir; means connecting said reservoir and with said mixing chamber located above the point of communication of said leads with said reservoir and in line with said leads.

3. In a down-How fuel feed carburetor, a suction chamber, means to supply fuel to said suction chamber, a body having af dro pipe formed therein; there being in sai ody, leads connecting said groove and dro pipe; a separable perforated ring mounte on said body and over said groove to form n reservoir to accumulate fuel from said drop pipe at closed throttle.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 8th day of Aprl,1922. v

PAUL' WILFRED ENSIGN.

0F CORRECTION.

Granted December 20, |927. to

PAUL .WILFRED ENSIGN.

lt is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 4, lille 4, for the word "My" read "By"; same page line 45, claim 2, strike out the word "and" and insert the same before the word "means" in the same line; page 4, line 52, claim 3, after the word "being" insert the words "a groove": and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this lst day of May. A. l). 1928.

(Seal) M. J. Moore, Acting Commissioner of Patents.

CERTIFICATE 0F CORRECTION.

Patent No. 1,653,04l. Granted December 20, i927, tn

PAUL WILFRED ENSIGN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as foiiows: Page 4, line 4, for the word "My" read "By"; same page line 45, claim 2, strike out the word "and" and insert the same before the word "means" in the same line; page 4, line 52, claim 3, after the word "being" insert the words "a groove": and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this Ist day of May. A. D. i928.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

